RESUMEN
Tricuspid valve endocarditis accounts for 5~10% of all cases of infective endocarditis. It commonly occurs in intravenous drug abusers, immunocompromised hosts, and patients with intravenous catheters, burns, or genital sepsis. Right-sided infective endocarditis without a predisposing factor is very rare. We experienced a case of tricuspid valve endocarditis with septic pneumonia caused by methicillin-resistant Staphylococcus aureus in an otherwise healthy 26-year-old female with no underlying cardiac disease. The diagnosis was delayed because pulmonary manifestations were predominant. The staphylococcal cassette chromosome mec typing and multilocus sequence typing revealed ST72-MRSA IVA without the Panton-Valentine leukocidin gene clone, which is the most common form of community-associated methicillin-resistant S. aureus in Korea.